Two new proof-of-concept viruses target the TI-89 graphing calculator.
Both spread in the style of an old DOS virus: once they're on a calculator, they look for other programs to infect. They can't jump from one calculator to another under their own power, but rely instead on the user moving an infected file through the TI-89's serial port, which can connect to a PC or directly to another TI-89.
The sneakier of the two is called Gaara by author Piotr Bania, and Tigraa by anti-virus firms. It's 494 bytes, and is entry-point obscuring, meaning it attaches itself somewhere in the middle of the program it's infecting, instead of at the top. Separately, University of Washington student Duncan Smith wrote a svelte 234-byte infector called Ovid, that Symantec calls TIOS.Divo.
Of course, as proof-of-concepts, these are both designed to be harmless. But now it's official: everything is infectible. The TI-89 is built on Motorola's 68000, the same processor as the first UNIX-based desktop workstation I ever used. The lesson here isn't just that I'm old. McAfee's Igor Muttik says portable Turing-complete gadgets are the next malware petri dish.
I like considering what a subtle and malicious calculator virus might achieve. Standard gear for students, you're allowed to have the TI-89 while taking the SAT. According to wikipedia, it's also allowed in international math competitions. Imagine the fun if a virus circulated that changed the square root of 1, or decided that pi equals 2.
Update:
It turns out calculator viruses have already wreaked mathematical havoc. Reader Scott Allen relates:
